Kiln



INVENroR ArroRNEY JmL-31, 1933.

J. -HOLLOWELL KILN 2 sheets-smet 1 Filed July 3, 19:50

J. s. HOLLOWELL.

Jan. 3l, 1933.

KILN` 2. sheets-sheet 2 Filed July 5, 195() lNvENToR BY l ATTORNEY lll/lll l l IM Patented Jan. 31', 1933 UNITED STATES PATENT OFFICE JAMES S. HOLLOWELL, F GRANFORD, Nm JERSEY, ASSIGNOR TO- NATURAL PRODUCTS i REFIN'ING C0., OF JERSEY CITY,-NEW JERSEY, A CORPORATION 0F DELAWARE KILN Application led July 3, 193Q. Serial No.r465,681.

My invention relates particularlyto a kiln, adapted for heating or roasting generally, but which is particularly applicable to the production of chromates, cement, lime, etc'.

The object of my invention is to. provide a kiln of the above character and more particularly an improved construction of kiln hoods having many-advantages overv the previous constructionsof kilns. The object of my invention is es ecially to provide a cooling zone in the ki n. A furthe-r object is to providea kiln hood which is particularly suited for use on inclined rotary kilns., A made in accordance with my invention may include means for adjusting the angle at which the kiln hood is supported toenable it to be more readily applied to an inclined rotarykiln having a desired angle of inclination. f A further object is to arrange the kiln hood-so'that it may be moved readily away from the kilnl and to one side thereof, so as to provide free' access into the interior of the kiln when desired;

Further objects of'my invention will appear from the detailed description of the same hereinafter.A A n While my inventionl-l is capable of embodiment in many different forms, for the purpose of illustration I have shown only one form of my invention in the accmpaying drawings, in which Fig; 1 is a side elevation of a kiln 'made i in accordance with myV invention, shown somewhat diagrammatically; l

Fig. 2 is a side elevation partly in section, showing a kiln made in accordance with my invention;

Fig. 3 is a transverse section of thesame;4

Fig. 4 is a detailed section of the kiln hood Y supportingl device; and

Fig. 5 is an enlarged longitudinal sectional detail. ,A

Inthedrawings I have shown a rotary inclined kiln 1,:su'ch as may be used for the y roasting of chrome ores in the manufacture 'of chromates from mixtures of any desired proportions of 'chrome .-o're, lime and soda ash, for example. Thein'clined rotary kiln 1 is supported on two sets of rollers 2 and 3,

adapted to receive cylindrical tracks 4 and 5 respectively, carried on the outside of the kiln, The kiln may be rotated by means of a gear 6 carried on the outside of the kiln, which may be driven by a gear 7 from any desired source offpower. The materials to be treated in the kiln are fed to the upper end of the same through a hopper 8 having a pipe 9 leading therefrom 'to the interior of 'thefkiln. The lower end of the kilnin the operation thereof is covered by a kilnhood 10 having a refractory Alining 11 in :such al ing- 14`through which the roasted materialcontaining sodium chromate, calcium chromate and some soda ash, -as well as .impurities, is adapted to be discharged. The rear face of the lhood 10 is provided lwith a strengthening brace 15 inthe formof an I-beam or in any other desired way. Also,

through the rear face 'of the hood 10 there.

exten s a pipe 16'for supplying oil or other Huid fuel which terminates in a spray nozzle 17. This oil -pipe 16 is located inthe center of an air supply pipe 18 provided with a v branch pipe 19 havingl a valve 20 therein to supply the mainbody of airfor burningsthe A fuel and a longitudinally adjustable pipe`21 splined within the pipe 18, in which the oi pipe 16 is mounted, to act as an auilriliary'air control moved by a hand-wheel 22 toprovide a secondary air control for the burner. As shown in Fig. 2, said` ai pipe 18 is not only supported from the rear face of the hood 10 but isalso supported by means of a web l or a bracket 23 upon the interior of aprotecting casing 24 made of heat resisting steel such as chrome steel, the rear end of which is secured within the rear face of the hood 10.

This protecting casing has at its forward end on the interior thereof a lining of refractory material 25 having an e anding opening 26 therein'to provide an injector action on the part of the burning fuel,`causng the intake of air into the casing 24 around the burner nozzle and air pipe 18. A further partial oxidation takes place between the hood and the forward end of the casmg 24, which extends into the inclined rotary kiln for a distance of about 1/8 to 1/5 the length of the kiln. The kiln has' a length of about l10 to18 times the inside diameter thereof.

The kiln hood 10 is, preferably, supported in such a manner as to provide an inclination thereof such as to -fit the lower end of the inclined kiln 1 according to the particular angle of the latter. prised of two longitudinal screws 27 and 28 which are supported against turning when adjusted in place in brackets 29 and 30 respectively on the kiln hood. This is accomplished by providing thescrews 27 and 28 with squared heads 31 located in brackets 29 and 30 on the rear face of the hood 10 as shown in Fig. 4, nuts 32 being provided on the other ends ofthe screws 27 and 28 for tightening them in place. By loosening the nuts 32 the screws 27 and 28 can be moved for the adjustment of screw-threaded sleeves 33 thereon. These sleeves 33 are connected by eyes 34 with suspension rods 35 having screw-threaded thereon turn-buckles 36 ywhich in turn are connected by rods 37 to brackets 38 and 39 which respectively carry wheels 40 and 41 arranged to run upon an I-beam 42 located transversely of the kiln 1. I-beam 42 in turn is arranged to be supported on two longitudinally movable supporting frameworks 43 and 44 for receivin Vthe weight of the hood 10 and its connecte supporting mechanism. These frames 43 and 44 are slidably movable longitudinally upon tracks 45 and 46.

` In the operation of the apparatus made inl accordance 'withjmy invention, during the roasting operation within the kilnlv the hood 10 will be supported in place at the vproper angle against the lower. end of the kiln as -shown ,inF Fig. 2. This angle of inclination is secured by the proper adjustment of the sleeves 33 on the screws 27 and 28 and by `the proper elevation secured by the operation ofthe turn-buckles-36. When it is desired to gain access to the interior of. thekiln as for removing any residual materials therein, relining, etc., the kiln hood with the attached parts including the burner, etc.,

is moved away from the lower end of the until the inner end of the casing 24A clears kiln 1 by sliding'the supporting frames for the I-beam 42 along. the tracks 45 and 46 the lower end of the kiln l, after which the hood 10 with attached parts is moved to one side by moving the rollers 40 and 41 along the I-beam 42. The lower end of the kiln This support is com# is now entirely open and .access maybe nad thereto unobstructed by the hood 10 and attached parts when any work is desired to be done therein. When the'kiln is to be put into operation again, the kiln hood is moved into place again by the reverse series of operations. Whenever desired, a further adjustment oftheangle of the hood 10 may be accomplished by adjusting the sleeves 33 on the screws27 and 28 and a similar adjustment may be made vertically by means of the turn-,buckles 36.

In carrying out the roasting operation in the kiln,`I might introduce into the kiln 1, through the hopper 9, a mixture of finely ground chrome o're containing', for instance- 100 parts by weight of chrome ore (contain-1 ing 01'203) v i parts by weight of lime 49 partsby weight of soda ash In this mixture the lime may, however,

slo

vary from 70 parts to 80 lpartsby weight,

understood, also, that in this application,

whenever I refer to lime or soda ash, such substitute materials may be used if desired. This amount of basic refractory materialis at least such as not only to prevent the formation ofpany undesirable compounds from the soda yash and the silica and the alumina which is contained in the chro'me ore but is v sutlicient also to attain the high yields of chromates hereinafter referred to. Also,thc soda ash .is present in such quantity to combine with somewhat less than, that is to say about 70% by'weight of the chromic oxide present. V This mixture is roasted in the ki-ln at a temperature of about 1000o C.' in the oxidizing atmosphere present therein in the upper part of the kiln, that is to say, between the upper end of the burner-.and the upper end 0f the kilnl after which the materials pass downwardly into the cooling zone, that is to say, between the upper end of the burner and the lower end of the kiln in which ,thev average temperature is approximately 800 C., so that the materials pass out the lower endI of the kiln at a temperature of about 600 C.l The reactions whichtake' place in the kiln 1 are as follows: f

CaCO?? CaO CO2 2 (FeOCrgO) 40a() These materials .delivered from vthe kiln 1 are in the form of particles varying in size -chronic ore in they from a line 4powder to lumps 1 inch in diameter, the latter having been oxidized practically only at the surface thereof, Aand con taining calcium chromate, sodium chroinate as well as silicates of lime and alumina. These materials may then be subjected to any desired-'operations in the usual way for the recovery iof the sodium chroinate or sodium hichromate therefrom.

lVhile l. have described my invention above in detail it is to be understood that many changes may be made therein without departing from the spirit of the saine as set forth in the claims.

I claim:

l. A rotary kiln adapted yfor roasting chrome ore in the formation of chromat-es, inclined so as to feed the same forwardly, comprising a source of heat applied atia point therein intermediate the kiln ends, said ends providing, respectively, 'a roasting-zone and a cooling zone and an air conveying housing located around said source of heat.

An inclined rotary kiln adapted for roasting cliroine orel in the formation of eliroinates, inclined so as to feed the saine forwardly, comprising'a source of heat applied at a point therein intermediate the kiln ends, said ends providing, respectively, a

roasting zone and a cooling zone and an air.

conveyin housing located around said :Source -of heat.

3'. AA rotary kiln adapted for roasting chrome ore in the formation of `chroinates,

inclined so as to feed the saine forwardly,

comprising a source of heat applied at a point therein intermediate the kiln ends, said ends providing, respectively, a roasting Azone and a cooling zone, an air conveying housing located around said source of heat and means for supplying heating gares in countercurreiit to the ore.

4. A rotary kiln' adapted for roasting- 'chrome ore inthe formation of chromates, i y

' the 'roasting and cooling zoneshand means inclined so as to feed the same forwardly, comprising a source of heat applied at a point therein intermediate the kiln ends, said ends providing, respectively, a'roasting zone and a cooling zone and an air conveying housing located aroiind said source of heat,

the source of heat iii 7 luding alnirner located between the roastin and coolingzones.

rotary kiltiv adapted. for roasting if'ormation of chromates, eed the same forwardly,

. `1, inclined so as to j comprising a source ofheat applied at a point therein intermediate the kiln ends, said ends providing, respectively, a roasting Zone and a cooling zone a ii air conveying housing located around said"--s ourceof heat', the source of heat including a burner located between the roasting and coolingzones, `and'ineans adapted to supply air to the kiln at the disl charge end of the cooling zone.

6. An inclined rotary kiln adapted for roasting chrome ore in the formation of chromates, inclined so as to feed the same forwardly,'comprising a source of heat ap )lied at a point therein intermediate the kiln ends, said ends providing, respectively,

a roastingzone and a cooling Zone andan air conveying housing located around said source` of heat, the source of heat including a burner vlocated between the roasting and cooling zones.

7.. An inclined rotary kiln adapted for roasting chrome ore in the formation of chroinates, inclined sopas to feed the sameV forwardly, comprising a source of heat applied at a point therein intermediate the kiln ends, saidends providing, respectively, a"

roasting zone and a cooling zone, an air conveying housing located around said source of heat, the source of heat including a burner located between the roasting and cooling zones, and means adapted to supply air 'to the kiln at the discharge end of the cooling zone. v

8. A rotary kiln adapted for roasting chronic ore in the formation of chromates,

inclined so asl to feed the saine forwardly,

comprising a source of heat applied at arpoint therein intermediate the kiln ends, said ends providing, respectively, a roasting zone and a. cooling zone and an air conveying housing located around said source of heat, the source of heat including a burner located betweenthe roasting and cooling zones, said burner being arranged to enter the kiln through the cooling zone.

f 9. A rotary chrome ore in the formation of chioin'ates, inclined so as to feed the sameforwardly, comi prising a soiircc of heat applied. ata point therein intermediate the kiln ends,'said ends kiln adapted for roastingl providing, respectively, a roasting zone andv a cooling zone, an air. conveying housing lo'cated'around said source of heat,- the source of heat including a burner located between adapted to supply air to the kiln at the discharge end'ofthe cooling zone, said burner being arranged to enter the kiln through the cooling zone. l0. A rotary kiln adapted for 'roasting chrome ore in the formation of chromates, inclined so`as to feed the same-forwardly, comprising, a source of heat applied at a point therein intermediate the kiln ends, said ends providing, respectively, a roasting zone and a cooling zone, and an air conveying housing located around said source of heat, the source of heat including a burner located between the roasting and cooling zones, said burner being arranged 4'to' enter` the kiln through the cooling zone and having a protect-ing casing located around the burner of the cooling zone.

11.` Aa rotary inclined Iso as to feed the same forwardly, comprising a source of heat applied at a point therein intermediate the kiln ends, said ends providing, respectively, a roasting zone and a coolingzone, an air conveying housing located around said source of heat, the source of heat including a burner located between the roasting and cooling zones, and

means adapted to supply air to the kiln at the discharge end of the cooling zone, said burner being arranged to enter the kiln through the cooling zone and having a pro-v tecting casing located around the burner in the cooling zone.

12. An inclined rotary kiln having a hood I and means 4for supporting the hood adjustably longitudinally of the kiln, said means including a removable frame provided with a hood suspending means including means for adjustably predetermin-ing the vertical angularity of said hood.

13. An vinclined rotary kiln having a hood and means for supporting the hood adj ustably longitudinally of the kiln, said means including a removable frame provided with a hood suspending meansincluding means for adjustably predetermining the vertical anc gularityof ysaida'hood, said adjusting means 'f cludingmeans for ad'ustably predetermining the vertical angularity of said hood.

comprising a longitudinal screw having an adjustable sleeve support thereon.

14. .An inclined rotary kiln having a hood and vertically adjustable means for supporting the hood adjustable longitudinally of the kiln, said means including a removable frame provided with a hood suspending means in- I 'JAMES S. HOLLOWELL. 'j 

